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###### Department of Transportation

###### Federal Aviation Administration

          - 14 CFR Part 39
          - [Docket No. FAA-2023-2238; Project Identifier MCAI-2023-00698-R]
          - RIN 2120-AA64

# AGENCY:

Federal Aviation Administration (FAA), DOT.

# ACTION:

Notice of proposed rulemaking (NPRM).

# SUMMARY:

The FAA proposes to adopt a new airworthiness directive (AD) for all Leonardo S.p.a. Model A109C, A109E, A109K2, A109S, and AW109SP helicopters. This proposed AD was prompted by reports of loose tail rotor duplex bearing locking nuts, possibly caused by improper installation. This proposed AD would require disassembling certain tail rotor duplex bearings and reassembling them in accordance with updated service information. This proposed AD would also prohibit installing certain tail rotor duplex bearings. These actions are specified in a European Union Aviation Safety Agency (EASA) AD, which is proposed for incorporation by reference. The FAA is proposing this AD to address the unsafe condition on these products.

# DATES:

The FAA must receive comments on this proposed AD by January 25, 2024.

# ADDRESSES:

You may send comments, using the procedures found in 14 CFR 11.43 and 11.45, by any of the following methods:
      -  Federal eRulemaking Portal:                          Go to                          regulations.gov.                          Follow the instructions for submitting comments.                    
      -  Fax:                          (202) 493-2251.                    
      -  Mail:                          U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590.                    
      -  Hand Delivery:                          Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.                    

*AD Docket:*                         You may examine the AD docket at                         *regulations.gov*                         under Docket No. FAA-2023-2238; or in person at Docket Operations between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this NPRM, any comments received, and other information. The street address for Docket Operations is listed above.                    

*Material Incorporated by Reference:*
      - For EASA material identified in this NPRM, contact EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; telephone +49 221 8999 000; email ADs@easa.europa.eu;                          website                          easa.europa.eu.                          You may find the EASA material on the EASA website                          ad.easa.europa.eu. 
      - You may view this material at the FAA, Office of the Regional Counsel, Southwest Region, 10101 Hillwood Parkway, Room 6N-321, Fort Worth, TX 76177. For information on the availability of this material at the FAA, call (817) 222-5110. The EASA material is also available at regulations.gov                          under Docket No. FAA-2023-2238.                    

# FOR FURTHER INFORMATION CONTACT:

                        Sungmo Cho, Aviation Safety Engineer, FAA, 2200 South 216th Street, Des Moines, WA 98198; phone: (781) 238-7241; email:                         *sungmo.d.cho@faa.gov.*

# SUPPLEMENTARY INFORMATION:

## Comments Invited

                    The FAA invites you to send any written relevant data, views, or arguments about this proposal. Send your comments to an address listed under                     **ADDRESSES**                    . Include “Docket No. FAA-2023-2238; Project Identifier MCAI-2023-00698-R” at the beginning of your comments. The most helpful comments reference a specific portion of the proposal, explain the reason for any recommended change, and include supporting data. The FAA will consider all comments received by the closing date and may amend this proposal because of those comments.                

                    Except for Confidential Business Information (CBI) as described in the following paragraph, and other information as described in 14 CFR 11.35, the FAA will post all comments received, without change, to                     *regulations.gov,*                     including any personal information you provide. The agency will also post a report summarizing each substantive verbal contact received about this NPRM.                

## Confidential Business Information

                    CBI is commercial or financial information that is both customarily and actually treated as private by its owner. Under the Freedom of Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public disclosure. If your comments responsive to this NPRM contain commercial or financial information that is customarily treated as private, that you actually treat as private, and that is relevant or responsive to this NPRM, it is important that you clearly designate the submitted comments as CBI. Please mark each                           ( print page 85857)                        page of your submission containing CBI as “PROPIN.” The FAA will treat such marked submissions as confidential under the FOIA, and they will not be placed in the public docket of this NPRM. Submissions containing CBI should be sent to Sungmo Cho, Aviation Safety Engineer, FAA, 2200 South 216th Street, Des Moines, WA 98198; phone: (781) 238-7241; email:                     *sungmo.d.cho@faa.gov.*                     Any commentary that the FAA receives that is not specifically designated as CBI will be placed in the public docket for this rulemaking.                

## Background

EASA, which is the Technical Agent for the Member States of the European Union, has issued EASA AD 2023-0105, dated May 23, 2023 (EASA AD 2023-0105), to correct an unsafe condition on Leonardo S.p.A. Model A109C, A109E, A109K2, A109LUH, A109S, and AW109SP helicopters. EASA advises of reports of loosening of the tail rotor duplex bearing locking nut. Subsequent investigations identified incorrect accomplishment of the assembly and continued maintenance instructions of the tail rotor duplex bearing housing and slider group as the most likely root cause of that loosening. The FAA is proposing this AD to detect and address the incorrect assembly of the tail rotor duplex bearing.

This unsafe condition, if not addressed, could lead to failure of the tail rotor function, possibly resulting in loss of control of the helicopter. See EASA AD 2023-0105 for additional background information.

## Related Service Information Under 1 CFR Part 51

EASA AD 2023-0105 requires replacing certain parts through the disassembly and reassembly of the tail rotor duplex bearing and the pitch change slider assembly. EASA AD 2023-0105 also prohibits installing certain parts on any helicopter.

                    This material is reasonably available because the interested parties have access to it through their normal course of business or by the means identified in the                     **ADDRESSES**                     section.                

## FAA's Determination

These helicopters have been approved by EASA and are approved for operation in the United States. Pursuant to the FAA's bilateral agreement with the European Union, EASA has notified the FAA about the unsafe condition described in its AD. The FAA is proposing this AD after evaluating all known relevant information and determining that the unsafe condition described previously is likely to exist or develop on other helicopters of these same type designs.

## Proposed AD Requirements in This NPRM

This proposed AD would require accomplishing the actions specified in EASA AD 2023-0105, described previously, as incorporated by reference, except for any differences identified as exceptions in the regulatory text of this proposed AD and except as discussed under “Differences Between this Proposed AD and EASA AD 2023-0105.”

## Explanation of Required Compliance Information

                    In the FAA's ongoing efforts to improve the efficiency of the AD process, the FAA developed a process to use some civil aviation authority (CAA) ADs as the primary source of information for compliance with requirements for corresponding FAA ADs. The FAA has been coordinating this process with manufacturers and CAAs. As a result, the FAA proposes to incorporate EASA AD 2023-0105 by reference in the FAA final rule. This proposed AD would, therefore, require compliance with EASA AD 2023-0105 in its entirety through that incorporation, except for any differences identified as exceptions in the regulatory text of this proposed AD. Using common terms that are the same as the heading of a particular section in EASA AD 2023-0105 does not mean that operators need comply only with that section. For example, where the AD requirement refers to “all required actions and compliance times,” compliance with this AD requirement is not limited to the section titled “Required Action(s) and Compliance Time(s)” in EASA AD 2023-0105. Service information referenced in EASA AD 2023-0105 for compliance will be available at                     *regulations.gov*                     by searching for and locating Docket No. FAA-2023-2238 after the FAA final rule is published.                

## Differences Between This Proposed AD and EASA AD 2023-0105

EASA AD 2023-0105 applies to Model A109LUH helicopters, however, this proposed AD would not because that model is not FAA type-certificated.

## Costs of Compliance

The FAA estimates that this AD, if adopted as proposed, would affect 160 helicopters of U.S. Registry. Labor rates are estimated at $85 per work-hour. The FAA estimates the following costs to comply with the proposed AD.

Disassembly and reassembly of the tail rotor housing and slider assembly would take approximately 8 work-hours for an estimated cost of $680 per helicopter and $108,800 for the U.S. fleet.

## Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. Subtitle VII: Aviation Programs, describes in more detail the scope of the Agency's authority.

The FAA is issuing this rulemaking under the authority described in Subtitle VII, Part A, Subpart III, Section 44701: General requirements. Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.

## Regulatory Findings

The FAA determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would not have a substantial direct effect on the States, on the relationship between the national Government and the States, or on the distribution of power and responsibilities among the various levels of government.

For the reasons discussed above, I certify this proposed regulation:

(1) Is not a “significant regulatory action” under Executive Order 12866,

(2) Would not affect intrastate aviation in Alaska, and

(3) Would not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act.

# List of Subjects in 14 CFR Part 39

      - Air transportation
      - Aircraft
      - Aviation safety
      - Incorporation by reference
      - Safety

## The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows:

      ( print page 85858)    

# PART 39—AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows: 

Authority:49 U.S.C. 106(g), 40113, 44701.

§ 39.13

2. The FAA amends § 39.13 by adding the following new airworthiness directive: 

**Leonardo S.p.a.:**                         Docket No. FAA-2023-2238; Project Identifier MCAI-2023-00698-R.                    

## (a) Comments Due Date

The FAA must receive comments on this airworthiness directive (AD) by January 25, 2024.

## (b) Affected ADs

None.

## (c) Applicability

This AD applies to all Leonardo S.p.a. Model A109C, A109E, A109K2, A109S, and AW109SP helicopters, certificated in any category.

## (d) Subject

Joint Aircraft Service Component (JASC) Code: 6400, Tail Rotor System.

## (e) Unsafe Condition

This AD was prompted by reports of loose tail rotor duplex bearing locking nuts, possibly caused by improper installation. The FAA is issuing this AD to detect and address the incorrect assembly of the tail rotor duplex bearing. The unsafe condition, if not addressed, could lead to failure of the tail rotor function, possibly resulting in loss of control of the helicopter.

## (f) Compliance

Comply with this AD within the compliance times specified, unless already done.

## (g) Requirements

Except as specified in paragraphs (h) and (i) of this AD: Comply with all required actions and compliance times specified in, and in accordance with, European Union Aviation Safety Agency (EASA) AD 2023-0105, dated May 23, 2023 (EASA AD 2023-0105).

## (h) Exceptions to EASA AD 2023-0105

(1) Where EASA AD 2023-0105 requires compliance in terms of flight hours, this AD requires using hours time-in-service.

(2) Where EASA AD 2023-0105 refers to its effective date, this AD requires using the effective date of this AD.

(3) Where the service information referenced in EASA AD 2023-0105 specifies to “discard” parts; for this AD, replace that text with “remove from service.”

(4) This AD does not adopt the “Remarks” section of EASA AD 2023-0105.

## (i) No Reporting Requirement

Although the service information referenced in EASA AD 2023-0105 specifies to submit certain information to the manufacturer, this AD does not include that requirement.

## (j) Alternative Methods of Compliance (AMOCs)

                        (1) The Manager, International Validation Branch, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. In accordance with 14 CFR 39.19, send your request to your principal inspector or local Flight Standards District Office, as appropriate. If sending information directly to the manager of the International Validation Branch, send it to the attention of the person identified in paragraph (k) of this AD. Information may be emailed to:                         *9-AVS-AIR-730-AMOC@faa.gov.*

(2) Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the local flight standards district office/certificate holding district office.

## (k) Related Information

                        For more information about this AD, contact Sungmo Cho, Aviation Safety Engineer, FAA, 2200 South 216th Street, Des Moines, WA 98198; phone: (781) 238-7241; email:                         *sungmo.d.cho@faa.gov.*

## (l) Material Incorporated by Reference

(1) The Director of the Federal Register approved the incorporation by reference of the service information listed in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.

(2) You must use this service information as applicable to do the actions required by this AD, unless this AD specifies otherwise.

(i) European Union Aviation Safety Agency (EASA) AD 2023-0105, dated May 23, 2023.

(ii) [Reserved]

                        (3) For EASA material identified in this AD, contact EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; telephone +49 221 8999 000; email                         *ADs@easa.europa.eu;*                         website                         *easa.europa.eu.*                         You may find the EASA material on the EASA website                         *ad.easa.europa.eu.*

(4) You may view this service information at the FAA, Office of the Regional Counsel, Southwest Region, 10101 Hillwood Parkway, Room 6N-321, Fort Worth, TX 76177. For information on the availability of this material at the FAA, call (817) 222-5110.

                        (5) You may view this material at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, visit                         *www.archives.gov/federal-register/cfr/ibr-locationsoremailfr.inspection@nara.gov.*

Issued on December 4, 2023.

Victor Wicklund,

Deputy Director, Compliance & Airworthiness Division, Aircraft Certification Service.

[FR Doc. 2023-26934 Filed 12-8-23; 8:45 am]

BILLING CODE 4910-13-P